I need to create more faces( but ctrl+r in edit mode isnt working), how do i do it alternatively?
You might want the Knife tool (the K tool in edit mode).  https://docs.blender.org/manual/en/dev/modeling/meshes/editing/subdividing/knife_subdivide.html .  It lets you divide faces along a line you choose.

If you decide those vertices aren't in the exact right place you can use Vertex Slide Shift+V to slide them into the right place.
If that model's triangulation is a problem and you want to turn them back into quads, consider the Dissolve Edges operator (in the X menu.